      <oai-identifier 
        xmlns="http://www.openarchives.org/OAI/2.0/oai-identifier"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai-identifier
        http://www.openarchives.org/OAI/2.0/oai-identifier.xsd">
        <scheme>{SCHEME}</scheme>
        <repositoryIdentifier>{REPOSITORY_IDENTIFIER}</repositoryIdentifier>
        <delimiter>{DELIMITER}</delimiter>
        <sampleIdentifier>{SAMPLE_IDENTIFIER}</sampleIdentifier>
      </oai-identifier>
